Normally, you could argue that cutting off aid would require an act of Congress, because Congress is the body that appropriates the funds when it passes the foreign aid budget. But in this case, Congress has already authorized a cut-off of Egyptian aid. All the President has to do is call the removal of Morsi a "coup" and a lot of the Egyptian military's funding will dry up.

Just having the ability to pull that trigger gives the U.S. enormous influence with the people calling the shots in this particular crisis. So it's wrong to say "probably there isn't" anything we can do.

Of course, whether the U.S. should use its influence is a different question. My point is only that the influence is there, unlike other places, like, for example, Syria, where the U.S. can't do a lot to direct the situation without intervening militarily. Oh and for the record, I think intervening militarily in Syria (or Egypt) would be a terrible idea. Also, even though the U.S. has the ability to threaten an aid cut off to influence the Egyptian junta, I stand by my earlier point that a cut-off will not happen.